A substantial amount of the goods that are transported between countries throughout the world are shipped in standardized steel containers twenty or forty feet in length. These containers are carried on ocean going vessels to destination ports where they are unloaded and delivered to their destinations either by truck or rail. Ocean-going vessels specially configured to ship such containers are sometimes referred to as container ships that can carry as many as 5,000 tightly stacked containers. In some cases, the containers are provided with integral twist locks that lock the eight corners of the container to a neighboring container. In other cases, the containers are simply held together by gravity, aided by “hardened” container corners that facilitate aligned stacking.
Because of the widespread use of containerized shipping, security concerns have increased recently where containers must be left unguarded on ocean-going vessels during extended voyages. For example, one security concern may be that of terrorists attempting to place a weapon of mass destruction in a container after it has been loaded onto a vessel. Similarly, contraband items such as drugs may be introduced into containers by drug smugglers after container loading onto a vessel, allowing the drugs to illegally enter a destination port completely undetected. Still another security concern is theft and pilfering of container contents.
A number of solutions have been proposed to deal with the problem of container security. One known solution involves detecting intrusions into a container and simply recording information related to the intrusion for later playback and review. This solution, does not, of course, alert security personnel in sufficient time to allow them to apprehend the intruder or prevent an act of theft or destruction. Another solution uses a GPS receiver to record the location of a container when an intrusion is detected, and a satellite communication system to transmit intrusion and location information to a land-based operations center. However, since the containers are normally stacked on vessels up to fifteen or more containers high, only the security system on the top container has a “view of the sky” adequate to receive GPS signals and transmit security messages to a satellite system. Accordingly, containers below the top container cannot report security status information during a voyage.
It has also been proposed to equip containers with cellular telephones that initiate calls via conventional cellular networks to an operations center in order to report a container intrusion. This approach is not suitable however, for use with containers on-board a vessel during ocean transits where the containers are typically out of range of land-based, commercial cellular telephone networks. Thus, using prior art solutions to the problem, the possibility exists that someone on-board the vessel could open doors on one or more on board containers during the voyage and the intrusion would not be reported to security authorities until the vessel reached its destination. By this time, however, pilfering of container contamination would have already occurred or weapons of mass destruction would have reached a location where they could inflict considerable damage.
Accordingly, what is needed is a shipping container security system that allows constant monitoring for possible intrusions and near real time reporting of intrusions during ocean transit. The present invention is intended to satisfy this need in the art.